Technical Field
The present disclosure relates to an optical sheet and a display device having the same, and more particularly, to an optical sheet that can simplify the manufacturing process and prevent a component from being reflected at a viewing angle, and a display device having the optical sheet.
Description of the Related Art
Typically, a liquid-crystal display (LCD) is a type of flat panel display that displays images by utilizing electrical and optical characteristics of liquid-crystal molecules having intermediate properties between liquid and solid.
Such an LCD device is thinner and lighter than other displays, and has been used in various applications throughout the industry due to low power consumption and driving voltage.
Since such an LCD is not a self-luminous device, it requires a backlight assembly having a fluorescent lamp on its back side. The backlight assembly irradiates light toward the front surface of the LCD, and the light is diffused while passing through a plurality of optical sheets. Then, the diffused light is condensed by a liquid-crystal panel so that an identifiable image is realized.
The optical sheet is mainly made of resin. It is a major component that determines optical characteristics of an LCD and is used in different kinds of backlight assemblies.
The optical sheet has a structure in which a lower light diffusing sheet (diffuser down), a prism sheet and an upper light diffusing sheet (diffuser up) are stacked in this order.
FIG. 1 is a plan view of a general display device. FIG. 2 is a view showing a general optical sheet. FIG. 3 is a view showing portion A of FIG. 1. FIG. 4 is a cross-sectional view of portion A′ in FIG. 1. FIG. 5 is a perspective view of a general sheet fixing pad.
Referring to FIG. 1, the general display device includes a guide panel 10 on which the above-described optical sheets 20 are placed, and a liquid-crystal panel (not shown) disposed on the optical sheets 20.
Referring to FIG. 2, the general optical sheets 20 form a square plate. Fixing portions 21 protruding outward are provided on the left and right sides of the optical sheets 20, respectively. The optical sheets 20 thus configured are seated on the guide panel 10.
As shown in FIG. 3 which shows portion A of FIG. 1, an adhesive tape 40 for fixing the liquid-crystal panel disposed on the optical sheets 20 is attached on the area of the guide panel 10 along the periphery of the optical sheets 20.
The guide panel 10 is provided with a panel seating part (not shown) on which the liquid-crystal panel is mounted. The panel seating part has a stepped shape upward so as to guide the four sides of the optical sheets 20.
Therefore, a gap is formed between the upper surface of the fixing portion 21 provided at the uppermost one of the optical sheets 20 and the upper end of the panel seating part. That is, the gap is generated between the guide panel 10 and the panel seating part due to the above-described step difference.
In the related art, a sheet fixing pad 30 shown in FIG. 5 is used to compensate for the gap generated as described above.
In this regard, referring to FIGS. 4 and 5, the sheet fixing pad 30 has a thickness equal to the above-described gap. The sheet fixing pad 30 is interposed between the upper surface of the fixing portion 21 of the uppermost one of the optical sheets 20 and the upper surface of the panel seating part. Accordingly, the gap due to the above-described step difference can be compensated by using the seat fixing pad 30.
FIG. 6 is a view showing portion B of FIG. 1.
Referring to FIG. 6, a shelter 11 having a predetermined depth is provided at a corner of the guide panel 10 to prevent damage to the corner of the liquid-crystal panel.
The shelter 11 is used as a space for preventing damage to the four corners of the liquid-crystal panel when a physical impact such as twisting of the liquid crystal panel is exerted thereon.
According to this structure, the sheet fixing pad 30 is required to compensate for the gap formed between the fixing portion 21 of the optical sheets 20 and the upper end of the panel seating part, and thus there is a problem in the related art in that the numbers of the manufacturing processes and processing components increase.
Also, in the related art, as the thickness of the bezel of the display device becomes slimmer, there is a problem in that the fixing portion 21 of the optical sheets 20 is exposed to the outside of the liquid-crystal panel at some viewing angles such that it is visible.